When the first DACs (digital-to-analog converters) appeared in 1985 they were big and expensive. Sony’s first DAC, the Sony DAS-702ES, weighed over 11kg and was built to last a lifetime. Too bad the technology inside the DAS-702ES remained cutting-edge for less than a year. Digital technology has continued to march forward, evolving and improving to the point where the early “Perfect Sound Forever” digital components sound pretty groady by today’s standards.

While I wouldn’t be so rash as to state that any new DAC will sound better than even the most expensive ten-year-old model, it’s not uncommon or surprising to find that many owners of older kilo-buck DACs are “trading up” to far less expensive DACs that provide superior performance compared to their outdated units. Combined with a computer-audio music library a USB-capable DAC can deliver a level of performance that a scant few years ago was available to only to a few of the very-well-heeled.

Here are four DACs, ranging in price from $699 to $3600, that offer better performance than you could obtain at anywhere near their prices just a few years ago. All represent the current state of DAC manufacturing and design. And regardless of their price points, they all attempt to optimize their listeners’ musical experience.

CHANNEL ISLAND AUDIO TRANSIENT MARK II USB CONVERTER AND DAC ($699)

The first DAC in our survey is from Channel Islands Audio. This small enthusiast-focused company specializes in high-value, made- in-the-U.S. audio components. Opened in 1997 and located on the central California coast in the town of Port Hueneme, Channel Islands Audio may be best known for its low-noise aftermarket power supplies for the Logitech Touch and SB3, but it also makes power amplifiers, preamps, DACs, and headphone amplifiers.

When I asked Dusty Vawter, chief designer at Channel Islands, whether the new Transient Mark II was principally a USB converter or a DAC, he told me, “I see it as a USB audio multi-tool. Its strength begins with the XM-2A board, making it a state-of-the-art USB to S/PDIF or I2S converter. We wanted a product that could be totally portable and provide the industry- standard 2V analog output. After testing the available DAC ICs, we chose the Wolfson for its musicality. We’ve surrounded this circuit with very high-grade parts from Nichicon, MUSE, Takman, Vishay, and Wima.”

Like the other audio components from CIA, the Transient Mark II exterior is simple and lacks the kind of cosmetic frills, such as 1⁄2"-thick front panels, that increase a component’s cost without adding to its sonic performance. The front panel has six blue LED lights that indicate the current sampling-frequency and two buttons to control the volume. That’s it. Since there’s only one input there’s no need for an input selector, and all outputs are always active.

The rear panel of the Transient has a USB input, one pair of single-ended RCA analog outputs, a BNC-terminated S/PDIF output, two I2S outputs (one HDMI and one five-pin mini-DIN), and a 5-volt DC power input for the optional VDC-5 Mk II high- current power supply.

The Transient II’s volume is adjusted via a digital control. According to Vawter, “a side benefit to the Wolfson DAC IC is that it has a 24-bit digital volume, which can be accessed in software mode. In that we already required a micro-controller to run the sample-rate indicators, it made sense to make use of the built-in volume control. The high-resolution control works very well and doesn’t have the L-R tracking error of potentiometers.”

Starting with the very well regarded Wolfson DAC and XMOS chipset as the basis for its design, Channel Islands added its own ideas to the mix. “We developed our own USB-to-I2S board utilizing the XMOS processor. Our XM-2A daughter board uses a compact four-layer PCB and dual ultra-low-jitter (<1 pico- second) oscillators, and can be powered by the USB or external low-noise supply. Then the low-jitter I2S signals from the XM- 2A are fed into independent buffers for each I2S output, a low- jitter S/PDIF transmitter (for BNC output), and also into the on-board Wolfson DAC circuit.”